1. Field of the Invention
The invention relates to a chucking apparatus for a workpiece with honeycomb structure, comprising a table that can be supplied with a vacuum and a clamping plate which can be placed on the table and which accommodates the workpiece in the region of an already profiled surface which is determined by the face ends of the honeycombs, whose receiving surface corresponding to the negative shape of the profiled surface of the workpiece is provided with suction openings to the table.
2. Description of the Related Art
Lightweight components, as are used in the construction of aircraft for example, comprise a core with honeycomb structure which is joined with cover layers into a composite body. Since the core represents the shaping element, the two surfaces determined by the face ends of the honeycomb must be machined by means of cutting or milling tools. The proper chucking of said workpieces with honeycomb structure for machining does not pose any problems as long as the workpiece has a flat surface on one side, because in this case the workpiece can be tightly held ready for machining on an air-permeable table that can be supplied with vacuum according to the state of the art (DE 10 2011 100 702 A1, DE 41 30 623 A1) after masking the honeycomb openings on the side of the flat surface with an air-impermeable film, which occurs over the entire chucking surface. After the profiling of the one surface, it is necessary to turn the workpiece for machining the opposite surface, so that the workpiece needs to be chucked via the already profiled surface. A clamping plate is used for this purpose (DE 41 30 623 A1) which forms a receiver for the workpiece which corresponds to the negative shape of the profiled workpiece surface and which rests flush on the contact surface of the clamping plate after the closure of the honeycomb openings with a film. The workpiece can be sucked towards the table through the clamping plate via its already machined surface by means of suction openings provided in the clamping plate. The clamping effect is considerably reduced in comparison with direct suction of the workpiece to the table due to the limited number of suction openings, even when the receiving surface of the clamping plate is provided with distributing grooves connected to the suction openings. It is an additional factor that the machining of the clamping plates, which are usually made of a light metal, is work-intensive. In order to avoid this effort for machining the second surface, it has already been proposed (DE 10 2011 100 702 A1) to machine the honeycomb-like workpiece on the one side in such a way that after bending of the workpiece not only the machined surface but also the flat surface required for clamping the workpiece assume the required surface contours. However, such bending is only possible within limits and unsuitable for some applications.